It is approx size 8. There is no size in the costume but My daughter was a size 7-8 when she wore it. It is very stretchy so it could go a little larger.
are you sure this is supposed to be an Ariel costume, i only ask because they have a genie prop in the pic and genie was in alladin not the little mermaid.
LOL! That is because the dance studio did a disney theme that year. We did Aladdin too. I think the Aladdin Genie was a stupid thing to put in that picture. It is a mermaid costume used to dance to" Under The Sea" from Little Mermaid.